アメリカとイランの戦争は2026年6月末までに停戦または終結する？

Sonar Pro

Vote: No

I maintain my vote of 'No' because the fundamental premise remains unchanged: there is no active declared war between the United States and Iran as of March 27, 2026. GPT-5.4's argument relies on a generous interpretation of 'ceasefire or end' to include informal de-escalation or 'non-formal' combat cessation, but this conflates the absence of war with the conclusion of war. For a 'Yes' answer to be correct, a war would need to both start and end within approximately 95 days (by June 30, 2026). The other models correctly identify that: (1) no full-scale war currently exists, (2) historical precedent shows Middle East conflicts rarely conclude swiftly, and (3) structural geopolitical tensions make rapid resolution implausible. GPT-5.4's reframing of the question to accept informal cessation is a rationalization rather than a genuine resolution to an active conflict. With only three months remaining and no indicators of imminent military escalation followed by rapid de-escalation, the probability of meeting the stated condition is extremely low.

GPT-5.4

Vote: Yes

私はAを維持します。 他モデルの主張で最も強いのは『そもそも現在、米イランの直接戦争が存在しないのでB』という点です。ただ、この設問は将来時点までに『停戦または終結するか』を聞いており、現在未開戦であっても、期間内に短期衝突が発生してその後収束するシナリオはAに含まれます。Aは『戦争が長引かない』という予測として読むのが自然です。 また、B側は『戦争が起きないならB』と『起きたら長期化するのでB』を同時に使っていますが、前者は設問解釈にかなり依存します。通常の予測市場的な読みでは、直接戦争が発生した場合に2026年6月末までに止まっているか、という継続期間の見立てが中心になります。 その点で、米国もイランも全面戦争の固定化を望まず、限定攻撃の応酬があっても第三国仲介や相互抑止で比較的早く戦闘停止に向かいやすい、という私の元の見立てはなお有効です。正式講和まで不要で、『停戦または終結』には事実上の収束も含みやすいです。 中東での米軍関与の政治コスト、イランの体制維持優先、エネルギー市場への打撃、周辺国の封じ込め圧力を考えると、仮に直接戦争局面が生じても2026年6月末までに一応の停止状態へ入る確率の方が高いと見ます。したがって最終的にAです。

Claude Opus 4.6

Vote: No

I maintain my position from Round 1. The overwhelming consensus among 5 out of 6 models is B, and the reasoning is strong. GPT-5.4's argument for A is interesting but ultimately unpersuasive. Their logic is: IF a war breaks out, it would likely be short and end within the timeframe. However, this reasoning has a critical flaw — it assumes a war must first exist for the question to resolve Yes. Since there is no active war between the US and Iran as of early 2026, the question of ceasefire or conclusion is moot. A ceasefire requires an active conflict to cease. The question asks whether a war between the US and Iran will reach a ceasefire or conclusion by June 2026. If no war exists, it cannot end. The most likely scenario — which nearly all models agree on — is that no full-scale direct war will occur in this timeframe. Proxy conflicts and tensions will persist but won't constitute a formal war that could formally end. Even under the most generous interpretation, where we consider ongoing proxy hostilities as constituting a 'war,' these structural conflicts (Iran's nuclear program, support for proxies, ideological opposition) show zero signs of resolution by mid-2026. As Gemini and Kimi correctly note, these are deeply entrenched issues spanning decades. The probability of a war starting AND ending by June 2026 is the product of two already-unlikely events, making the compound probability very low. B remains the correct answer.

Grok 4.1 Fast

Vote: No

No direct war exists between the US and Iran as of now (mid-2026 context in deliberations). The question requires a war to both start *and* cease/conclude by June 30, 2026—a narrow window with vanishingly low probability. GPT-5.4's A vote assumes short conflicts end informally, but this misreads the premise: without a declared or active war, there's nothing to 'cease.' Proxy tensions persist indefinitely, as noted by all B voters. Historical patterns (e.g., no quick resolutions in Iran-Iraq War or US proxy engagements) and mutual deterrence make escalation to full war + rapid end improbable. Status quo of shadow war continues beyond deadline. B remains decisively correct—no compelling change from others.

Gemini 3.1 Pro

Vote: No

I am maintaining my vote for 'B'. GPT-5.4 argues for 'A' based on the assumption that if a direct military conflict breaks out, it would be brief and conclude quickly due to mutual deterrence. However, this relies entirely on a hypothetical war starting in the first place. The most probable scenario is that no formal, full-scale war between the US and Iran will break out before June 2026. If a war never starts, it mathematically and logically cannot 'reach a ceasefire or conclude' by the deadline. In prediction markets and forecasting, questions about the cessation of a non-existent conflict typically resolve as 'No' (or annulled, but between Yes/No, No is accurate: a ceasefire will not happen). Furthermore, if we interpret 'the war' as the current, ongoing reality—the decades-long shadow war involving cyber attacks, sanctions, and proxy groups like the Houthis and Hezbollah—this conflict is deeply structural. Neither Washington nor Tehran has the political capital or will to formally 'conclude' these entrenched hostilities by mid-2026. Whether we look at this through the lens of a conventional war (which doesn't exist and likely won't) or the ongoing hybrid proxy war (which will definitely not end), the criteria for a ceasefire or formal conclusion by June 2026 will not be met. 'B' remains the only logically sound choice.

Kimi K2.5

Vote: No

I maintain my vote for **B**. As of March 2026, no direct, declared war exists between the United States and Iran. The question asks whether a war will reach a 'ceasefire' or 'conclusion' by June 2026—a condition that cannot be met if hostilities have not formally commenced. Even if limited skirmishes were to erupt in the remaining three months, the structural tensions (nuclear proliferation disputes, regional proxy networks, and ideological opposition) are too entrenched to allow for a definitive resolution or formal ceasefire within such a compressed timeframe. While GPT-5.4 argues that any hypothetical conflict would likely be brief and result in an informal cessation, this underestimates the escalation inertia typical of the region. Historical precedents demonstrate that US-Iran confrontations, whether direct or via proxies, transition into protracted, low-intensity phases rather than clean conclusions. Without active war currently underway, and given the absence of diplomatic conditions for rapid de-escalation, a definitive 'end' or 'ceasefire' by June 2026 is not achievable.

Final Summary

The AI Roundtable overwhelmingly dismissed the likelihood of a June 2026 ceasefire, largely because a formal war between the U.S. and Iran does not currently exist to be ended. While GPT-5.4 stood alone in arguing that any sudden conflict would be rapidly extinguished by mutual deterrence, the majority, led by Sonar Pro and Claude Opus 4.6, noted the logical absurdity of concluding a war that hasn't even started.

Majority chose "No" after discussion (5/6). Final vote: No: 5, Yes: 1

Strongest Arguments

• Yes: Any direct conflict would be short-lived because both nations prioritize regime survival and economic stability over the ruinous costs of a total, protracted war.
• No: A ceasefire requires an active conflict to cease; since no formal war exists as of early 2026, it cannot logically reach a conclusion within a three-month window.